1. Field of the Invention
The present invention relates to an image input apparatus for reading an image on a film or other original.
2. Description of the Related Art
Scanners are known as a kind of the image input apparatus for reading an image on a film or other original.
The scanners are roughly classified into a first type in which an image reading portion is moved while an original is fixed, so that a two-dimensional image on the original is read by the moving reading portion, and a second type in which the original is moved while the image reading portion is fixed, so that a two-dimensional image on the original is read by the fixed reading portion.
In the first type in which the reading portion is movable, an original is mounted on a fixed original stage, which is called platen, for example, and image reading is effected with a cover placed on the original. Some images may require adjustment of the position or angle of the original. For instance, the adjustment is made to rectify an undesirable angle of inclination of the horizon appearing on a photograph as the original. In this case, the cover is opened so that the angle and position of the original can be adjusted, and is then closed again, to permit subsequent image reading.
In the second type in which the original is moved, the original is placed on a movable stage while being fixed by a cover, for example, so that the image reading is effected on the moving original. When the angle of the image is required to be adjusted, it is necessary to remove the cover or the like, and remount or replace the original on the stage. In the case where the stage incorporates an angle adjusting mechanism, the adjustment is effected in response to commands generated by a computer, for example.
In the image input apparatus constructed as described above, it takes a lot of time to open the cover and reset the original again so as to adjust the angle of the image to be read. In addition, the accuracy of the adjustment is unsatisfactory, requiring trial-and-error, and thus the adjustment must be repeated many times. Where the angle adjusting mechanism is incorporated in the stage itself, the image input apparatus becomes undesirably large-sized and expensive, for example.
The originals used with the scanner are roughly classified into reflection-type originals, such as photographic prints or photoprints, and transparency-type originals, such as films. Although the front and rear of the reflection-type originals can be easily discriminated, it is not always easy to discriminate between the front and rear of the transparency-type originals. The front-rear discrimination has been conventionally made by reference to characters outside picture areas in the case of 35 mm films, and to the position of notches formed in film peripheral portions in the case of 4.times.5 size films.
In many cases, however, the film is set in a holder or the portion of the film outside its picture area is covered with a mask when the image is read by the scanner, and the characters and notches outside the picture area are hidden, thus making it difficult to discriminate between the front and rear of the film. As a result, the front and rear of the film may be reversed by mistake when an original holder for the film is set in the image input apparatus. If the original is set in the wrong way, it takes several minutes to read the image, which is time-consuming, and then the image reading must be tried again, resulting in reduced work efficiency.
The transparency-type originals include those held by mounts for slides. While these slide originals are read by a known image input apparatus for slides, called a slide scanner, this apparatus requires setting of the original and image reading for each image on the original. When multiple slide images are to be read at the same time, each original needs to be removed from the mount, and is set on a drum scanner, for example, so as to effect the image reading.
When the above-indicated slide scanner is used to read the images on the multiple slide originals, it takes a lot of time and effort to reset or replace the slide for each image, and the productivity is thus limited. On the other hand, the use of the drum scanner requires cumbersome and time-consuming procedures, such as removing each original from the mount, and attaching the original to the drum.